Looking to write a piece of software that can take in images like this, and count the number of circular "holes" in the picture. You can see that there are circular holes, as well as non-circular holes. The image is basically a plastic plane consisting of cylinders melted together, and the diamond-ish holes should not be counted.
I am at the point where I can load the image into a C# WPF application, and resize or recenter the image to where I want to work with, but how to count the shadows or circular holes is not something I've been able to find in my research so far.
What I've thought about is having the user place a line on top of the image that crosses the holes, and counting how many times on that line the color drops approaching black, but that seems time consuming.
Any help in solving this problem would be appreciated even if it's referring to a manual or textbook/reference on image processing in this form.